Height adjustable headrest device

ABSTRACT

The invention relates to a height adjustable headrest device with a crossbar element and a headrest supporting element as well as a clamp connection for continuously variable mounting of the headrest element at the crossbar element. The clamp connection comprises a retaining clamp comprising two recesses as well as a tapped bore and gripping around a crossbar element, a centering bushing comprising an external thread and an internal thread, the centering bushing being screwed into the tapped bore of the retaining clamp, as well as a screw element screwed in the centering bushing. The headrest supporting element is inserted in the recesses of the retaining clamp. The crossbar element comprises a bore in which the centering bushing is inserted. The clamp connection is caused by screwing the screw element into the centering bushing and thus bringing the headrest supporting element near the crossbar element.

FIELD OF THE INVENTION

The invention relates to a height adjustable headrest device as well as a wheel chair with such a height adjustable headrest device.

BACKGROUND OF THE INVENTION

Height adjustable headrest devices are known from prior art. They are used, among others, with seats in the medical field as well as in the field of care, for example also in wheel chairs. A shower and toilet wheel chair with a height adjustable headrest is distributed under the product name OCEAN VIP by the AQUATEC GmbH, Alemannenstr. 10, 88316 Isny, Germany.

The height adjustable headrest device of this known shower and toilet wheel chair will be described below in connection with FIGS. 7 to 11. It is to be understood that the representations in the figures of this application including said FIGS. 7 to 10 are not drawn to scale. For a better representation of certain details, the representation of some components is enlarged and simplified.

FIG. 7 shows a known height adjustable headrest device 200 in a perspective representation. The device comprises a headrest 201 which is fixed to a horizontal bar 202. The headrest can be shifted horizontally by releasing a clamping device 203 whereby the horizontal bar 202 can be shifted along the shorter shank 204A of a headrest supporting element 204 designed in the shape of a J.

The headrest supporting element 204 is fixed to a crossbar element 210 by means of a clamp connection 300. The crossbar element 210 can, for example, be the central part of a push handle of a wheel chair.

The clamp connection 300 is shown in FIG. 8 in a perspective representation and in FIG. 10 in a side view, in each case partially cut open, where in each case only a part of the headrest supporting element 204 as well as the crossbar element 210 is shown.

The clamp connection 300 comprises a U-shaped retaining clamp 360 having two rectangular recesses 361A, 361B, through which the headrest supporting element 204, which also has a rectangular design, can be inserted. The internal radius of the retaining clamp 360 having a U-shaped design is dimensioned such that it is adapted to the outside diameter of the crossbar element 210. Between the crossbar element 210 and the headrest supporting element 204, a spacer 370 is arranged which is held in the retaining clamp 360 by means of a groove and tongue connection so as to be shifted. The corresponding grooves 362A and 362B of the retaining clamp 360 are shown in FIG. 9.

A tapped bore 380 is provided in the retaining clamp 360 in which a screw element 390 is screwed in.

The screw element 390 is provided with a star handle 391 which permits manual release and tightening of the clamp connection 300.

The function of the known clamp connection will be illustrated below. As is in particular represented in FIGS. 8 and 10, the retaining clamp 360 is placed around the crossbar element 210 such that the tapped bore 380 is flush with a bore 211 provided in the crossbar element 210. Opposite the bore 211, a bulging 212 concave to the inner surface is provided in the crossbar element 210.

The spacer 370 is inserted into the retaining clamp 360 and the headrest supporting element 204 is inserted through the recesses 361A, 361B of the retaining clamp 360. The screw element 390 is screwed into the tapped bore 380 and in the process inserted through the bore 211 of the bar element 210 until it lies against the bulging 212. When the screw element 390 is further screwed in, the retaining clamp 360 is moved to the right with respect to the bar element 210 in FIG. 10, which causes the headrest supporting element 204 to be pressed against the spacer 370 and the spacer 370 to be pressed against the crossbar element 210. Thereby, a clamp connection is formed which provides secure positioning of the headrest supporting element 204 with respect to the crossbar element 210.

If the screw element 390 is slightly screwed out of the retaining clamp 360, the clamp connection is released and the headrest supporting element 204 can be shifted in the longitudinal direction with respect to the retaining clamp 360 and thus with respect to the crossbar element 210. Thus, a continuously variable height adjustment of the headrest 201 is achieved.

SUMMARY OF THE INVENTION

One aspect of the invention is to further improve the known height adjustable headrest device, in particular with respect to function and operating safety.

The invention provides a height adjustable headrest device with a crossbar element and a headrest supporting element as well as a clamp connection for the continuously variable mounting of the headrest supporting element at the crossbar element, wherein the clamp connection comprises a retaining clamp comprising two recesses as well as a tapped bore, the retaining clamp gripping around the crossbar element, a centering bushing comprising an external thread and an internal thread, the centering bushing being screwed into the tapped bore of the retaining clamp, and a screw element screwed into the centering bushing, wherein the headrest supporting element is inserted in the recesses of the retaining clamp, the crossbar element comprises a bore into which the centering bushing is inserted, and the clamp connection is effected by screwing in the screw element into the centering bushing and thus bringing the headrest supporting element near the crossbar element.

The height adjustable headrest device according to the invention thus differs from the known height adjustable headrest device illustrated above in the design of the clamp connection, that is in that a centering bushing is provided which comprises an external thread and an internal thread. The centering bushing is screwed into the tapped bore of the retaining clamp with its external thread. With a cylindrical centering section, the centering bushing is inserted in a correspondingly designed bore of the crossbar element. The screw element is screwed with the clamp connection by means of the internal thread of the centering bushing.

By the provision of the centering bushing, a particularly exact holding and fixing of the components with respect to one another is ensured.

In a preferred embodiment of the invention, the sense of rotation of the internal thread of the centering bushing is opposed to that of the external thread of the centering bushing. If, for example, the internal thread is designed as left-handed thread, the external thread is designed as right-handed thread. This prevents the threaded bushing from being screwed out of the retaining clamp when the screw element is unintentionally actuated.

Preferably, a spacer is arranged between the headrest supporting element and the crossbar element and held via a groove and tongue connection in the retaining clamp in a preferred embodiment. The spacer is preferably made of plastics to ensure clamping as wear-resistant and backlash-free as possible.

The crossbar element preferably has a tubular design. In the crossbar element, opposite the bore for receiving the centering bushing, preferably a bulging which is concave to the inside is provided which acts as abutment for the screw element.

The headrest supporting element and the corresponding recesses of the retaining clamp preferably have a rectangular design. It is to be understood that other shapes, for example circular or other rounded geometries, are also possible.

A wheel chair according to the invention with a height adjustable headrest device according to the present invention is preferably designed such that the crossbar element is designed as a push handle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed description when read in connection with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawing are not to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity.

The invention will be illustrated below with reference to a preferred embodiment and the enclosed drawings, wherein

FIG. 1 is a perspective representation of a height adjustable headrest device according to the invention,

FIG. 2 is a schematic representation of the clamp connection wherein the crossbar element is omitted for better representation,

FIG. 3 is an exploded drawing of a spacer, the centering bushing, the retaining clamp and the screw element,

FIG. 4 is a perspective representation of the centering bushing,

FIG. 5 is a sectional representation of the centering bushing,

FIG. 6 is an axial plan view of the fixing bushing,

FIG. 7 is a perspective representation of a known height adjustable headrest device corresponding to FIG. 1,

FIG. 8 is a partially sectional representation of a known embodiment of a clamp connection,

FIG. 9 is an enlarged perspective representation of a known retaining clamp,

FIG. 10 is a partially sectional side view of a known embodiment of a clamp connection, and

FIG. 11 is a perspective sectional representation of a crossbar element.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 7 to 11 have been illustrated in the beginning. As far as not described otherwise in the following, the embodiments in this regard also apply to the height adjustable headrest device according to the invention. Correspondingly, in FIGS. 1 to 6, those components which correspond to the respective known components according to FIGS. 7 to 11 are provided with reference numerals which are lower by the amount of 200 with respect to the respective corresponding reference numerals in FIGS. 7 to 11. Thus, for example, reference numeral 1 is assigned to the headrest in the embodiment of the invention according to FIG. 1, while reference numeral 201 is used for the headrest of the known embodiment according to FIG. 7.

The crossbar element 10 according to the present invention basically corresponds to that according to the prior art described in the beginning. Only the bore 11 has a different design in the crossbar element according to the invention, as will be illustrated below. In FIG. 11, for the sake of simplicity, therefore both reference numerals 210 are used for the crossbar element according to the prior art, and reference numeral 10 for the crossbar element according to the invention. The same goes for the reference numerals 211 and 11 for the bore as well as reference numerals 212 and 12 for the bulging.

As described before, the clamp connection of the height adjustable headrest device according to the invention comprises a centering bushing 20. In this respect, reference is made in particular to FIGS. 2 to 5. The centering bushing 20 comprises an external thread 22, with which it can be screwed into the tapped bore 180 of the retaining clamp 160. A collar 25 provided at the centering bushing 20 serves as contact face.

The centering bushing 20 moreover has a centering section 21 inserted in the bore 11 of the crossbar element 10. It is to be understood that with the crossbar element 10 of the clamp connection of the height adjustable headrest device according to the invention, the bore 11 has to be designed such that it is adapted to the outside diameter of the centering section 21 of the centering bushing 20 as sliding fit. In the prior art illustrated in the beginning, the bore 211 is in contrast dimensioned such that the threaded portion of the screw element 390 can be passed through.

The screwing of the centering bushing 20 into the tapped bore 180 of the retaining clamp 160 is facilitated by a groove 26 in which a screwdriver can be set.

The centering bushing 20 moreover has an internal thread 23 the sense of rotation of which is opposed to that of the external thread 22. If the external thread 22 is designed as right-handed thread, the internal thread 23 is designed as left-handed thread. Correspondingly, the internal thread 23 is designed as left-handed thread if the external thread 22 is designed as right-handed thread.

After the screwing of the threaded bushing 20 into the tapped bore 180 of the retaining clamp 160, the same can be put over the crossbar element 10 such that the centering section 21 of the centering bushing 20 penetrates the bore 11 of the crossbar element 10. The spacer 170 can then be inserted into the retaining clamp 160, and subsequently the headrest supporting element 4 is passed through the recesses 161 a, 161 b. Finally, the screw element 190 is screwed into the centering bushing 20 by means of the star handle 191 until it lies against the bulging 12 of the crossbar element 10. If the screw element 190 is further screwed in, the headrest supporting element 4 is clamped with the crossbar element 10 via the spacer 170.

While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention. 

1. A height adjustable headrest device with a crossbar element and a headrest supporting element as well as a clamp connection for continuously variable mounting of the headrest supporting element at the crossbar element, wherein the clamp connection comprises: a retaining clamp comprising two recesses as well as a tapped bore, the retaining clamp gripping around the crossbar element, a centering bushing comprising an external thread and an internal thread, wherein the centering bushing is screwed in the tapped bore of the retaining clamp, and a screw element screwed in the centering bushing, wherein the headrest supporting element is inserted in the recesses of the retaining clamp, the crossbar element comprises a bore in which the centering bushing is inserted, and the clamp connection is caused by screwing in the screw element into the centering bushing and thus bringing the headrest supporting element near the crossbar element.
 2. The device according to claim 1, wherein the sense of rotation of the internal thread is opposed to that of the external thread.
 3. The device according to claim 2, wherein the centering bushing comprises a groove which is designed for setting a screwdriver.
 4. The device according to claim 2, wherein the centering bushing comprises a collar which provides a stop when it is screwed in.
 5. The device according to claim 4, wherein the centering bushing comprises a groove which is designed for setting a screwdriver.
 6. The device according to claim 1, wherein the centering bushing comprises a collar which provides a stop when it is screwed in.
 7. The device according to claim 6, wherein the centering bushing comprises a groove which is designed for setting a screwdriver.
 8. The device according to claim 1, wherein the centering bushing comprises a groove which is designed for setting a screwdriver.
 9. The device according to claim 1, wherein a spacer is arranged between the headrest supporting element and the crossbar element.
 10. The device according to claim 9, wherein the spacer is made from a plastic.
 11. The device according to claim 9, wherein the spacer is guided via a groove and tongue connection in the retaining clamp.
 12. The device according to claim 11, wherein the spacer is made from a plastic.
 13. The device according to claim 1, wherein the crossbar element has a tubular design.
 14. The device according to claim 13, wherein a bulging which is concave to the inside which serves as an abutment for the screw element is provided in the tubular crossbar element opposite the bore for receiving the centering bushing.
 15. The device according to claim 1, wherein the headrest supporting element and the recesses of the retaining clamp have a rectangular design.
 16. Wheel chair with a height adjustable headrest device according to claim 1, wherein the crossbar element is adapted to be a push handle. 